HANDLING NUCLEAR WASTE????

People are wondering where the nuclear waste go or how to dispose of them properly so that it is perfectly safe for us the living creature and the environment?

So, this time, we'll discuss mainly on disposing the nuclear waste correctly.

Nuclear waste generated from a nuclear reactor is classified as HIGH LEVEL WASTE, and there are proper procedure to dispose them .About 27 tonnes of used fuel or three cubic metres per year of vitrified waste for a typical large nuclear reactor.They can be effectively and economically isolated, and have been handled and stored safely since the production of nuclear power began.Storage is mostly in ponds at reactor sites, or occasionally at a central site.  Some 90% of the world's used fuel is stored thus and some of it has been there for decades.  The ponds are usually about seven metres deep, to allow three metres of water over the used fuel to fully shield it.  The water also cools it.  Some storage is in dry casks or vaults with air circulation and the fuel is surrounded by concrete.

If the used fuel is reprocessed, as it is in UK, French, Japanese, and German reactors, HLW comprises highly-radioactive fission products and some transuranic elements with long-lived radioactivity. 

These are separated from the used fuel, enabling the uranium and plutonium to be recycled. The remaining HLW generates a considerable amount of heat and requires cooling. It is vitrified into borosilicate (Pyrex) glass, encapsulated into heavy stainless steel cylinders about 1.3 metres high, and stored for eventual disposal deep underground. This material has no conceivable future use and is unequivocally waste. The hulls and end-fittings of the reprocessed fuel assemblies are compacted, to reduce volume, and usually incorporated into cement prior to disposal as ILW.

But if used reactor fuel is not reprocessed, it will still contain all the highly radioactive isotopes, and the entire fuel assembly is treated as HLW for direct disposal. As HLW, it generates considerable heat and requires cooling. However, since it largely consists of uranium (with a little plutonium), it represents a potentially valuable resource. Hence there is an increasing reluctance to dispose of it irretrievably.Either way, after 40-50 years, the heat and radioactivity have fallen to one-thousandth of the level at removal. This provides a technical incentive to delay further action with HLW until the radioactivity has reduced to about 0.1% of its original level.

After being stored for approximately 40 years, the used fuel assemblies are ready for encapsulation or loading into casks ready for indefinite storage or permanent disposal underground.